Burnishing mat



C. C. KINKER BURNISHING MAT Sept, 27, 1955 Filed June 12; 1955 Qwwmo oC/arence C. Amker l l l I United State t hfiQ" fljhis invention relates"to means forfburni h g j metal articles, and particularlyto a maflbrbther me befrfh avi ing a rnulti'plicity of resilient projectionsebnj-ifor nishing engagement'with the want?- i s'heretofore beenproposedto prpvide a polishing "burpishiigg mat-in whichtheentireflbodylyzasirhade 91 an abfasive'impregnated 1 15515. ;The abiasiyeimpi e gnated ubstance was molded into sheets or pads as fgw ell'as into a'form' in which a of work contactung fingers extended 'from amain body. Ithas'been found that the elasticity.- of amubhersmass andespecially a i i tt a atedteyetafla ii ;t aet -I Thus the ly reducedbythe addition'of an abrasive.

known abrasive impregnated pads and projections above mentioned areuseful only for the finishing of flat surfaces glglre the bendingdemands on the elements are not very The primary object of the presentinvention is the provision of a burnishing means of the class describedwhich has only the surface portion of its resilient burnishing fingersor projections impregnated with an abrasive material, while the mainbodies of the fingers or projections are of unimpregnated flexiblematerial. The abrasive used may be of coarse or fine mesh, depending onthe grade of burnishing to be performed, thus enabling workpieces to besuccessively burnished and polished by series of mats which, insuccession, may have the resilient burnishing projections thereofimpregnated with first a rough or coarse cutting abrasive, then with afine cutting abrasive, and finally with a finishing burnishing material.

Further objects and advantages of the invention will be apparent fromthe following detailed description, and from the accompanying drawingsillustrating one embodiment thereof, in which- Fig. 1 is a plan view ofa mat embodying the invention mounted on a carrying member, with partsbroken away, and with only a portion of the abrading projections shown,and

Fig. 2 is an enlarged fragmentary edge view thereof, taken on the line2-2 in Fig. l, with some of the abrasive impregnated sleeves entirely orpartially in central longitudinal section.

Referring to the drawings, 1 designates a mat or surface member that ismounted on a stifi" backing or carrying member 2 and having on its outeror exposed surface a multiplicity of rather closely spaced resilientfingers or projections 3 for rubbing or brushing engagement with metalarticles to be burnished. In practice, either the articles, the mat, orboth, may be relatively moved during burnishing operations.

The projections 3, and also preferably the mat member 1, are composed ofresilient material, as for instance soft rubber, whereby the projectionshave yielding frictional coaction with the articles being burnished orpolished.

The projecting fingers 3, in one embodiment that gives good results inpractice, are approximately 2% inches long, circular in cross-sectionand are tapered lengthwise from a base radius of approximately of aninch to 2,718,736 a, liattg rrt ed Sept. 195,?

1 ere 5%; inch apart. These 'ineasiir'ements are mentioneii i 'n rei afilter and pump.

This use of fingers having impregnated surfaces has an advantage as itallows the successive use on the same work of a series of mats havingdifferent grades of impregnated abrasives so that one, for instance, maycontain a rough cutting abrasive of about mesh, the next a medium coarseabrasive of, for example, 240 mesh, then an abrasive of, for example 325mesh, and finally an abrasive suitable for the finishing operation, suchas an air borne or flour size abrasive mesh.

We have found that rubber impregnated with an abrasive or otherdissimilar hard materials is very brittle, the same as a rubber ink orpencil eraser, and thus entirely unsuited for use where greatflexibility is a requirement because of its inherent inability towithstand rugged service and continuous flexing as is found where thework-pieces have domed or ridged or discontinuous surfaces that must beburnished.

The present invention is based on the provision of resilient fingers ofmats of this character having only the working portions thereof providedwith an abrasive impregnated coating or of a covering member impregnatedwith a suitable abrasive. This leaves the body of the burnishing finger,or at least the major portion thereof, composed of strong, durable,resilient stock, whereby breakage and deterioration in use are reducedto a minimum.

In practice, the object of the present invention is preferablyaccomplished by providing an abrasive impregnated sleeve or nipple 5 ofsoft rubber or the like, and fitting one of these sleeves over theWorking end portion of each of the abrading fingers 3. The sleeve ispreferably fixed in place by cementing or otherwise in such a mannerthat it can be removed only by immersion in a suitable solvent. These-sleeves preferably stop short of the base of the fingers so as toenable full advantage to be taken of the strength and resilience of thenon-impregnated rubber stock at the base portions of the fingers whereit is most needed. In event the abrasive impregnated portion of a fingeris in the form of a sleeve or nipple that is fitted down over thefinger, it is provided at its outer or blind end with a perforation 6through which the entrapped air may escape. As wear in use occurs, theworn down sleeve portion may be removed from the flexible thensubstituted therefor on the finger.

I wish it understood that my invention is not limited to any specificconstruction, arrangement orform of the parts, as it is capable ofnumerous modifications and changes without departing from the spirit ofthe claims.

I claim:

1. In a burnishing mat or the like having aplurality of resilientrubber-like abradin'g'fingers, a' Sleeve ofpliant plastic materialimpregnated with abrasive material, fitted over and covering theburnishing end portionof each finger, and means to releasably, engagesaid impregnated sleeve and finger. p I

2. In" a burnishing mat or the like havinga base portion and a pluralityof laterally spaced resilient rubberlike abrading fingers projectingoutwardly from a surface of said base portion,'the provision of a sleeveof pliant plastic material impregnated with an abrasive material fittedover and covering the burnishing end portion of each finger in spacedrelation to the base portion thereof,

wherebyeach finger has a neck portion at its inner end the flexing'pfwhich is not interfered with by its sleeve.

3. In a burnishing melt or the like having a base portion and aplurality of laterally spaced resilient rubberlike abrading fingersprojecting outwardly from a surface of saidbase portion, the provisionof a sleeve of pliant plastic material impregnated with an abrasivematerial fitted over and covering the burnishing end portion of eachfinger in spaced relation to the base portion thereof,

whereby each finger has a neck portion at its inner end angel 3 byapplying a solvent and a new sleeve portion the flexing of which is notinterfered with by its sleeve, each sleeve being releasably attached toits finger to permit replacement.

4. In a burnishing mat or the like having a base portion and a pluralityof laterally spaced resilient rubberlike fingers projecting outwardlytherefrom, said fingers each tapering so as to befredu'ced in size fromnear its inner end to its outer end, the provision of a sleeve of pliantplastic material impregnated with an abrasive fitted over the outertapered end portion of each finger and terminating short of said base toprovide a neck portion the resiliency of which is not interfered withby-the respective sleeve portion, said sleeve being releasably securedto the fingers for replacement.

References Cited in the file of this patent UNITED STATES PATENTS963,523 Crismore July 5,1910 1,156,958 Whitin Oct. 19,1915 1,670,068Grimes May 15, 1928 1,953,983 Benner Apr. 10, 1934 1,961,911 Pusch -June5, 1934 2,049,324 Schneider July 28, 1936 2,083,749 Sword June 15, 19372,115,209 Mulholland et a1. Apr. 26, 1938 7 2,328,998 Radford Sept. 7,1943 2,608,034 Frornson Aug. 26, 1952 FOREIGN PATENTS 451,704 GreatBritain Aug. 11, 1936

